Help! New engine, but not running right

[Hobbes_86]

Hi Guys,
So here is my issue that hopefully someone will have a bit of insight....
I have a 400 Bandit with just over 20,000 miles. It has been running like a champ for the past year and a half (over 10,000 miles) I never had an issue with it until a few weeks ago, I was out riding and I started to hear a ticking noise. Stopped the bike for a few min..gave it a look over and then went back on my way. About a half mile down the road the clutch would not let me shift, would not disengage, the bike stalled and the rear tire locked up.
After some troubleshooting it was determined that something in the transmission went kaput. So I bought a used engine that I was told ran fine and had less than 10,000 miles on it. So we got the "new" engine in and everything rewired up. Turned the bike on and it idled like a champ.
Here is the problem...
It will not take any throttle at all. Give it 1/8 a turn and it just bogs out and stalls and it won’t take more. It sounds like it is flooding out.
Carbs have been taken apart cleaned and re-synced.
Doesn’t appear to be a timing issue.
No exhaust leaks.
It's running on all 4 cylinders.
Plugs look good. (less than a year old)
Charges fine. (Battery is 4 months old)
Ignition coils were labeled when they were taken off...so they are not reversed.
Plenty of fuel is getting into the carbs.
Unplug the stator and it still runs.

Help, what else can I do/check?? How does one test the CDI unit?

PS..before swapping engines I was able to get the bike into neutral and it started up and took throttle fine.

Thanks in advance for any help and suggestions,
Kim

[Chris H]

Hi,
Do you know if the motors are the same year as there are different pickup triggers/cdi's for different years, altho im sure if they are different you get back firing. It maybe worth taking the leftside covers off and checking.

[Hobbes_86]

I was told it is "probably" the same year..Ill do some more digging.

Thanks for the reply!

[Hobbes_86]

Any one have any info on the differences and how to tell if I have a GK75 versus GA??  Right now I am under the assumption that pre 95 models were the GK75. 


help   

[Hobbes_86]

 

Just found this sites wiki..it answered my question!